Package-on-package proximity sensor module

Abstract

A package-on-package proximity sensor module including a infrared transmitter package and a infrared receiver package is presented. The proximity sensor module may include a fully-assembled infrared transmitter package and a fully-assembled infrared receiver package disposed on a quad flat pack no-lead (QFN) lead frame molded with an IR cut compound housing. A bottom surface of the QFN lead frame may be etched and covered with the IR cut compound to provide a locking feature between the QFN lead frame and the IR cut compound housing.

What is claimed is: 
     
       1. A package-on-package proximity sensor module comprising:
 a fully-assembled infrared transmitter package including an infrared transmitter die, a transmitter lead frame and a first transparent compound, the infrared transmitter die being electrically connected to the transmitter lead frame, the infrared transmitter die being covered by the first transparent compound; 
 a fully-assembled infrared receiver package including a proximity sensor detector, a receiver lead frame and a second transparent compound, the proximity sensor detector being electrically connected to the receiver lead frame, the proximity sensor detector being covered by the second transparent compound; 
 a half-etched lead frame including etched regions, the thickness of the etched regions of the half-etched lead frame being thinner than the thickness of non-etched regions of the half-etched lead frame, wherein the fully-assembled infrared transmitter package is mounted on a first portion of the half-etched lead frame that includes at least some of the etched regions so that the transmitter lead frame is electrically connected to the half-etched lead frame and the fully-assembled infrared receiver package is mounted on a second portion of the half-etched lead frame that includes at least some of the etched regions so that the receiver lead frame is electrically connected to the half-etched lead frame; and 
 an infrared (IR) cut mold compound, wherein the IR cut mold compound covers the fully-assembled infrared transmitter package, the fully-assembled infrared receiver package, and a portion of the half-etched lead frame. 
 
     
     
       2. The proximity sensor module of  claim 1 , wherein the transmitter lead frame includes an etched region, the thickness of the etched region of the transmitter lead frame being thinner than the thickness of a non-etched region of the transmitter lead frame. 
     
     
       3. The proximity sensor module of  claim 2 , wherein the fully-assembled infrared transmitter package further comprises a lens molded from a transparent compound and wherein the infrared transmitter die is an LED die. 
     
     
       4. The proximity sensor module of  claim 1 , wherein the receiver lead frame includes an etched region, the thickness of the etched region of the receiver lead frame being thinner than the thickness of a non-etched region of the receiver lead frame. 
     
     
       5. The proximity sensor module of  claim 4 , wherein the fully-assembled infrared receiver package further comprises a lens molded from the second transparent compound and an ASIC and wherein the proximity sensor detector is a photo-diode die. 
     
     
       6. The proximity sensor module of  claim 1 , wherein the half-etched, lead frame is a quad flat pack no-lead (QFN) lead frame. 
     
     
       7. The proximity sensor module of  claim 6 , wherein a bottom surface of the half-etched, lead frame is etched and covered with the IR cut mold compound to provide a locking feature. 
     
     
       8. The proximity sensor module of  claim 1 , wherein the IR cut mold compound is disposed via a molding process over and covering both the fully-assembled infrared transmitter package and the fully-assembled infrared receiver package, and wherein the IR cut mold compound further comprises a first aperture above the fully-assembled infrared transmitter package and a second aperture above the fully-assembled infrared receiver package, respectively. 
     
     
       9. The proximity sensor module of  claim 1 , wherein the IR cut mold compound further comprises a moldable material, an epoxy, and an IR cut material. 
     
     
       10. A package-on-package proximity sensor module comprising:
 an infrared transmitter package including an infrared transmitter die, a transmitter lead frame and a first transparent compound, the infrared transmitter die being electrically connected to the transmitter lead frame, the infrared transmitter die being covered by the first transparent compound; 
 an infrared receiver package including a proximity sensor detector, a receiver lead frame and a second transparent compound, the proximity sensor detector being electrically connected to the receiver lead frame, the proximity sensor detector being covered by the second transparent compound; and 
 a pre-molded lead frame comprising a half-etched lead frame moldably integrated with an infrared (IR) cut compound housing, the half-etched lead frame including etched regions, the thickness of the etched regions of the half-etched lead frame being thinner than the thickness of non-etched regions of the half-etched lead frame, wherein the IR cut compound housing comprises a first recess, a second recess and a divider disposed between the first recess and the second recess, and wherein the infrared transmitter package is mounted on a first portion of the lead frame that includes at least some of the etched regions within the first recess so that the transmitter lead frame is electrically connected to the half-etched lead frame and the infrared receiver package is mounted on a second portion of the lead frame that includes at least some of the etched regions within the second recess so that the receiver lead frame is electrically connected to the half-etched lead frame. 
 
     
     
       11. The proximity sensor modules of  claim 10 , wherein the infrared transmitter package is a fully-assembled lead frame package comprising a lens molded of a transparent compound and wherein the infrared transmitter die is an LED die. 
     
     
       12. The proximity sensor module of  claim 10 , wherein the infrared receiver package is a fully-assembled lead frame package comprising a lens molded of a transparent compound and an ASIC and wherein the proximity sensor detector is a photo-diode die. 
     
     
       13. The proximity sensor module of  claim 10 , wherein the pre-molded lead frame is a quad flat pack no-lead (QFN) lead frame. 
     
     
       14. The proximity sensor module of  claim 10 , wherein the IR cut mold compound housing comprises an IR cut mold compound, wherein that the mold compound is disposed over and integrated with the lead frame by a molding process. 
     
     
       15. The proximity sensor module of  claim 10 , wherein a bottom surface of the pre-molded lead frame is etched and covered with a portion of the IR cut mold compound of the IR cut mold compound housing, configured to provide a locking feature between the half-etched lead frame and the IR cut mold compound housing. 
     
     
       16. The proximity sensor module of  claim 10 , wherein the IR cut mold compound housing comprises a pre-molded IR cut compound housing disposed over and fixedly attached to the half-etched lead frame. 
     
     
       17. The proximity sensor module of  claim 16 , wherein the pre-molded IR cut mold compound housing is fixedly attached to the half-etched lead frame by an adhesive or a locking mechanism. 
     
     
       18. The proximity sensor module of  claim 10 , wherein the molded IR cut compound housing further comprises a moldable material, an epoxy, and an IR cut additive. 
     
     
       19. A package-on-package proximity sensor module comprising:
 a fully-assembled, infrared transmitter package including an infrared transmitter die, a transmitter lead frame and a first transparent compound, the infrared transmitter die being electrically connected to the transmitter lead frame, the infrared transmitter die being covered by the first transparent compound, wherein the transmitter lead frame includes an etched region, the thickness of the etched region of the transmitter lead frame being thinner than the thickness of a non-etched region of the transmitter lead frame; 
 a fully-assembled, infrared receiver package including a proximity sensor detector, a receiver lead frame and a second transparent compound, the proximity sensor detector being electrically connected to the receiver lead frame, the proximity sensor detector being covered by the second transparent compound, wherein the receiver lead frame includes an etched region, the thickness of the etched region of the receiver lead frame being thinner than the thickness of a non-etched region of the receiver lead frame; 
 a half-etched quad flat pack no-lead (QFN) lead frame including etched regions, the thickness of the etched regions of the half-etched OFN lead frame being thinner than the thickness of non-etched regions of the half-etched QFN lead frame; and 
 a pre-fabricated infrared (IR) cut compound casing moldably integrated with the half-etched QFN lead frame, wherein the pre-molded IR cut compound casing comprises a first recess, a second recess and a divider disposed between the first recess and the second recess, wherein the infrared transmitter package is mounted on a first portion of the half-etched QFN lead frame that includes at least some of the etched regions within the first recess so that the transmitter lead frame is electrically connected to the half-etched QFN lead frame and the infrared receiver package is mounted on a second portion of the half-etched QFN lead frame that includes at least some of the etched regions within the second recess so that the receiver lead frame is electrically connected to the half-etched QFN lead frame, and, wherein the pre-molded IR cut compound casing is fixedly attached to the half-etched QFN lead frame by an adhesive or a locking mechanism. 
 
     
     
       20. The proximity sensor module of  claim 19 , wherein the fully-assembled infrared receiver package comprises a lens molded of a clear compound and an ASIC and wherein the proximity sensor detector is a photo-diode die.